Linkage of patients from HIV testing to HIV care programs and their retention once enrolled in care are essential to HIV program effectiveness in terms of prevention of HIV-related morbidity and mortality and prevention of HIV transmission. Linkage and retention rates in HIV programs in Sub-Saharan Africa (SSA) are suboptimal, with less than half of patients who test positive successfully linking and remaining in care at 1 year. We propose an implementation science study focused on identifying an effective pragmatic multicomponent strategy to improve linkage and retention of HIV-positive patients in PEPFAR-supported HIV programs in Swaziland. The study design is a two-arm cluster site-randomized trial to compare the effectiveness of a novel combination package of evidence-based interventions, the combination intervention strategy (CIS), compared to standard of care (SOC) on linkage and retention of HIV-positive patients from point of testing to retention in care. CIS will include 1) point of care CD4+count assays at HIV testing sites; 2) accelerated ART initiation for eligible patients; 3) provision of a basic care and prevention package (BCPP); 4) short message service (SMS) reminders for clinic appointments and active tracking of patients who miss visits; and 5) financial incentives for linkage and retention. The primary aim is to evaluate the effectiveness of CIS as compared to SOC on the combined outcome of rapid linkage to HIV care within 1 month and retention in care at 12 months among adults testing positive for HIV. Secondary aims include evaluation of the effectiveness of CIS compared to SOC on each of linkage to HIV; retention in care; time to ART initiation; HIV disease progression (WHO Stage III or IV, hospitalization, CD4+count, and mortality); patient acceptability; association between baseline characteristics and outcomes, and comparison of cost effectiveness with regards to disease progression and infections averted. The proposed study, LINK4HEALTH, is distinguished by several innovations including: the use of a combination of evidence-based interventions targeting multiple barrier types that impede patient linkage and retention in care across different points in the HIV care cascade; utilization of a cluster site-randomized study design to rigorously determine the effectiveness of CIS on a combined outcome of linkage and retention; determination of cost-effectiveness of CIS in terms of disease progression and infections averted; focus on a high-prevalence country in Sub- Saharan Africa; and collaboration with Ministry of Health, PEPFAR, CDC, and other in-country partners. Our approach to the research has the ultimate goal of bridging the know-do gap in terms of identifying a feasible, cost-effective strategy for linkage and retention in HIV care that can be readily integrated into HIV programs and scaled up widely to other PEPFAR-supported and other HIV programs around the world. PUBLIC HEALTH RELEVANCE: Linkage of patients from HIV testing to HIV care programs and their retention once enrolled in care are essential for HIV program effectiveness in terms of benefits of care, treatment and prevention. This implementation science study aims to evaluate a combination of evidence-based interventions bundled into one innovative strategy on linkage and retention of HIV-positive patients in PEPFAR-supported HIV care sites in Swaziland. The results of the proposed research will advance the field of HIV care, treatment, and prevention by quantitatively demonstrating whether a combination intervention strategy is cost-effective in decreasing HIV disease progression and infections averted, thus enhancing program impact.